In power solutions of high integrated applications, an integrated switching circuit is widely used with fewer pins. Generally, as shown in FIG. 1, a switching circuit 51 may comprise four pins, a first pin 501 configured to output a fault disable signal, a second pin 502 configured to receive a control signal PWM to control the switching circuit 51, a third pin 503 configured to receive an input voltage signal VIN, and a fourth pin 504 configured to provide an output voltage signal VOUT. Usually, the fault disable signal may be used to indicate whether one or more faults occur. The switching circuit 51 will be turned off for protection once one or more faults occur in the switching circuit 51.
However, detailed fault information may not be obtained from the fault disable signal. Moreover, in multi-phase voltage converters, any fault in one phase of the switching circuits may induce the whole multi-phase voltage converter to shut down. Still, the fault disable signal is not able to provide specific information regarding what types of the one or more faults are and which phase the one or more faults occur in. Traditionally, if we need more fault information about the switching circuit 51, additional pins may be added, which can result in larger size, and higher cost of the integrated circuit.